Plier-type wrench



v My B? R957 H. TUGEND PLIER-TYPE vWRENCH Filed Nov. l, 1954 -v Hewwidn"Tugend by: SMN@ This invention relates to a lever wrench serving as agripping, holding and clamping tool, of the kind comprising a pair ofclamp jaws pivotally connected together, and said jaws being movablewith respect to the other by a handle lever articulated on the body ofthe movable clampjaw, a toggle lever support pivotally connected at oneend to the uppershorter lever arm of said handle lever so as to formwith said arm a pair of toggle levers, the other end of said togglelever support being pivotally mounted in a support in another handlelever rigid with the stationary jaw body, said support beinglongitudinally slidable in said second-mentioned handle lever by meansof an adjusting screw and nut, and a release lever pivotally mounted inthe first-mentioned handle lever for initiating the release of thetoggle lever pair when .in the clamped position. Y A

In order that this kind lof lever wrench clamping device-may be electivefor diterent jaw distances or jaw widths and4 to permit the adjustmentof the clamp jaws to a determined jaw width, one lever armi oftheopenable and closable toggle lever pair is made adjustable in lengthwith the aid of the adjusting nut. In known constructions the adjustingnut and also the handle of the vrelease lever lie outside the reach ofthe-hand effecting the clamping and adjustment, so that the 4operationof the known tool is troublesome and time-consuming.

Moreover, in known tools of this type the adjusting screw and adjustingnut also lie exposed between the movable and stationary clamp bodies, oroutside the latter, so that the thread of the adjusting screw can easilybe damaged.

The present invention aims at obviating the foregoing disadvantages andto this end consists in a lever wrench of the foregoing kind the end ofthe toggle lever support, bearing against the lixed jaw handle lever, ismounted in a ball socket which is connected to an adjusting screw housedbetween the limbs of a U-shaped handle lever of the fixed jaw body, theadjusting nut of said adjusting screw being adapted to be operated fromthe outside of said handle lever and is immovably mounted between theedges of a cut-out in said U-shaped handle.

According to a further feature of the invention, the release lever isconstructed as a cranked, single-armed rolling lever disposed betweenthe U-shaped cheeks of the movable handle lever inthe plane of thetoggle lever pair, the fulcrum of said rolling lever being the apexcurve lying in the clamped position against the toggle support leverbeneath the common pivot bolt of the toggle pair and the free bent overlever end of said rolling lever extends through an elongated slot in thehandle lever at the level of the thumb of the users hand, while theother end is pivoted on said handle leverand is bent away towards theend of the handle.

In order that the invention may be more readily understood, reference ismade to the accompanying drawings which illustrate diagrammatically andby way of eX- ample, one embodiment of lever wrench in accordancetherewith, and in which:

tes atent l 2,800,823 Patented July 30, 1957 Figure 1 is a sideelevation partly in section showing the toggle lever arrangement and therelease lever in the clamped position with the smallest jaw width;

Figure 2 is a section taken on the line A-B of Figure 1; and

Figure `3 is ya view similar to Figure 1l showing the wrench adjusted tothe largest jaw width, the full lines showing the clamped position andthe chain-dotted lines the release position.

Referring to the drawings, the lever wrench comprises a stationary jawbody a, on which there is articulated at z in a manner known per se amovable jaw body b, the handle lever c of whichis pivotally connected bya pivot bolt d to the movable jaw body b. The handle lever c of themovable jawn body b is connected in manner knownper se to the handlelever e of the fixed jaw body a by means of a pivot bolt w and a togglelever f of adjustable length, so that the toggle lever f forms with thelever arm g of the handle -leg c an openable and clos able togglelever-pair, by means of which the jaws can be secured at a determinedjaw width or in the clamping position, depending on the adjusted lengthof the toggle lever f, and released again by means of a release lever u.

According tothe present invention the other end of the toggle lever f ismounted by a ball and socket connection in `a support block l, which isconnected to an adjusting screwy mfhoused between the web and cheeks ofthe handle lever e which is U-shaped in crosssection, an externallyoperable adjusting nut n of which is mounted between theA edges 0"of acut-out p in the handle of width corresponding tothe length of theadjusting nut' n.' The depth ofrthepcut out is measured firstly inaccordance with the` diameter of the adjusting nut n, and secondly inaccordance with the externaldiameter of the adjusting screw m which,when screwed together with the adjusting nut n, is mounted on ordetachably connected to the handle lever e together with said adjustingnut between the support of the adjusting nut n on the one hand and anabutment and support q of the embedded adjusting screw m on the otherhand.

One or both side cheeks of the handle e is or are provided with awindow-like aperture r and with indicating marks for the readyobservation of the position of the jaw width or of the respectiveclamping position of the jaws.

The handle cheek has scale lines and markings 0, 1 and 2 for thesmallest, middle and greatest clamping width of the jaws, while thesupport block l carries a datum mark which in the position of thesmallest clamping width as shown in Figure 1 coincides at the top withthe scale mark 0 and in the position of the greatest clamping width asshown in Figure 3 coincides with the scale mark 2 at the bottom.

A helical spring s, which is connected at one end to the movable jawbody b between the pivot bolt d and the bearing bolt t and at the otherend between the cheeks of the handle e of the fixed jaw body a, holdsthe toggle lever f securely with its ball end in the open andcorrespondingly shaped socket bearing of the support block l. This is ofcourse only necessary in the release position shown in chain-dottedlines in Figure 3.

The release lever u is arranged in the plane of the toggle lever pairbetween the cheeks of the movable handle lever c. The release lever u isconstructed as a single-armed bent rolling lever, the downwardlydirected lever arm of which is pivoted between the cheeks of the movablehandle leg c, while the other lever arm projects through an elongatedslot of the movable handle c and is provided at the end with a thumbplate. The fulcrum of the release lever is formed at any given moment bya point of the approximately quadrantal to semicircular apex line, whichat any given moment in the clamped position of the extended toggle leverpair touches the toggle lever f, below the common pivot bolt w. In thisclamped position of the release lever .11, which also corresponds to theclamped position .at the moment in question of the clamp jaws, it lieswith the back facinggaway from the apex line on'the slot edges on thelower side. In order to take into account the different `position of themovable jaw body b and the different inclination of the toggle lever findifferent clamping positions of the jaws, a flat spring v, acting as 'anequalizing spring, is preferably disposed between the back of therelease lever u and the rear wall of the slot in the handle.

By the foregoing arrangement it will be seen that the adjusting nut n issituated near the reach of the index linger and the thumb plate of therelease lever u is situated at the level of the thumb of the handholding or operating the clamping device.

If a workpiece of the size 0 is to be clamped, the thickness of whichcorresponds to the minimum clamping width, while the left hand holds theworkpiece, lthe index nger of the hand holding the wrench is used tomove the adjusting nut until the datum line of the support block lcoincides with the zero line of the scale. Through further adjustment byfeel of the adjusting nut n by means of the index finger to the correctclamp position of the toggle lever arrangement, which still permitstight clamping `of the workpiece, the nal position of the jaws forclamping the workpiece of the size 0 is reached. By compressing thehand, the wrench jaws are now brought into the clamp position of theextended toggle lever arrangement. In this position the release lever utouches the toggle lever f below the common fulcrurn point w of thetoggle lever pair. The release lever'ru is now in the clamp position.The release is now com pleted by pressure of the thumb ofthe hand incontact on the thumb plate of the release lever u.

The position shown in chain-dotted lines of the movable clamp jaw body band of the rockable handle c in Figure 3 corresponds to the releaseposition of the clamping wrench with the maximum clamping width, whichis indicated on the scale by II. In this case the helical spring sprevents further movement apart of the wrench jaws.

I claim:

1. In a wrench type pliers having a pair of relatively movable handlesand an over-center locking element operatively connected to saidhandles, the improvement corn- Yprising a single-armed substantiallyzigzag-shaped releasing lever pivotally mounted at one end thereof onone of said handles in such a manner that the free end portion of saidlever extends in the direction of said one handle, said lever being soconstructed and arranged as to impart a releasing movement to saidlocking element upon movement of said free end portion toward said onehandle.

2. The arrangement defined in claim 1 wherein said one handleischannel-shaped and opens inwardly and wherein the intermediate portionof said lever extends through a longitudinal slot of said one handlewhich slot is only of substantially such length as to permit the pivotalmovement of said lever which is necessary in order that said lever mayeffect releasing movement of said locking element.

References Cited in the le of this patent UNITED STATES PATENTS

